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/*
* Copyright (C) 2014-2021 Canonical, Ltd.
* Copyright (C) 2022-2025 Colin Ian King.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include "stress-ng.h"
#include "core-builtin.h"
#include "core-cpu-cache.h"
#include "core-mmap.h"
#include "core-numa.h"
#include "core-shared-cache.h"
#define MEM_CACHE_SIZE (2 * MB)
/*
* stress_cache_alloc()
* allocate shared cache buffer
*/
int stress_cache_alloc(const char *name)
{
stress_cpu_cache_cpus_t *cpu_caches;
stress_cpu_cache_t *cache = NULL;
uint16_t max_cache_level = 0, level;
char cache_info[512];
const int numa_nodes = stress_numa_nodes();
cpu_caches = stress_cpu_cache_get_all_details();
if (g_shared->mem_cache.size > 0)
goto init_done;
if (!cpu_caches) {
if (stress_warn_once())
pr_dbg("%s: using defaults, cannot determine cache details\n", name);
g_shared->mem_cache.size = MEM_CACHE_SIZE * numa_nodes;
goto init_done;
}
max_cache_level = stress_cpu_cache_get_max_level(cpu_caches);
if (max_cache_level == 0) {
if (stress_warn_once())
pr_dbg("%s: using defaults, cannot determine cache level details\n", name);
g_shared->mem_cache.size = MEM_CACHE_SIZE * numa_nodes;
goto init_done;
}
if (g_shared->mem_cache.level > max_cache_level) {
if (stress_warn_once())
pr_dbg("%s: using cache maximum level L%d\n", name,
max_cache_level);
g_shared->mem_cache.level = max_cache_level;
}
cache = stress_cpu_cache_get(cpu_caches, g_shared->mem_cache.level);
if (!cache) {
if (stress_warn_once())
pr_dbg("%s: using built-in defaults as no suitable "
"cache found\n", name);
g_shared->mem_cache.size = MEM_CACHE_SIZE * numa_nodes;
goto init_done;
}
if (g_shared->mem_cache.ways > 0) {
uint64_t way_size;
if (g_shared->mem_cache.ways > cache->ways) {
if (stress_warn_once())
pr_inf("%s: cache way value too high - "
"defaulting to %" PRIu32 " (the maximum)\n",
name, cache->ways);
g_shared->mem_cache.ways = cache->ways;
}
way_size = cache->size / cache->ways;
/* only fill the specified number of cache ways */
g_shared->mem_cache.size = way_size * g_shared->mem_cache.ways * numa_nodes;
} else {
/* fill the entire cache */
g_shared->mem_cache.size = cache->size * numa_nodes;
}
if (!g_shared->mem_cache.size) {
if (stress_warn_once())
pr_dbg("%s: using built-in defaults as "
"unable to determine cache size\n", name);
g_shared->mem_cache.size = MEM_CACHE_SIZE;
}
(void)shim_memset(cache_info, 0, sizeof(cache_info));
for (level = 1; level <= max_cache_level; level++) {
size_t cache_size = 0, cache_line_size = 0;
stress_cpu_cache_get_level_size(level, &cache_size, &cache_line_size);
if ((cache_size > 0) && (cache_line_size > 0)) {
char tmp[64];
(void)snprintf(tmp, sizeof(tmp), "%sL%" PRIu16 ": %zuK",
(level > 1) ? ", " : "", level, cache_size >> 10);
shim_strlcat(cache_info, tmp, sizeof(cache_info));
}
}
pr_dbg("CPU data cache: %s\n", cache_info);
init_done:
stress_free_cpu_caches(cpu_caches);
g_shared->mem_cache.buffer =
(uint8_t *)stress_mmap_anon_shared(g_shared->mem_cache.size, PROT_READ | PROT_WRITE);
if (g_shared->mem_cache.buffer == MAP_FAILED) {
g_shared->mem_cache.buffer = NULL;
pr_err("%s: failed to mmap shared cache buffer, errno=%d (%s)\n",
name, errno, strerror(errno));
return -1;
}
stress_set_vma_anon_name(g_shared->mem_cache.buffer, g_shared->mem_cache.size, "mem-cache");
g_shared->cacheline.size = (size_t)STRESS_PROCS_MAX * sizeof(uint8_t) * 2;
g_shared->cacheline.buffer =
(uint8_t *)stress_mmap_anon_shared(g_shared->cacheline.size, PROT_READ | PROT_WRITE);
if (g_shared->cacheline.buffer == MAP_FAILED) {
g_shared->cacheline.buffer = NULL;
pr_err("%s: failed to mmap cacheline buffer, errno=%d (%s)\n",
name, errno, strerror(errno));
return -1;
}
stress_set_vma_anon_name(g_shared->cacheline.buffer, g_shared->cacheline.size, "cacheline");
if (stress_warn_once()) {
if (numa_nodes > 1) {
pr_dbg("%s: shared cache buffer size: %" PRIu64 "K (LLC size x %d NUMA nodes)\n",
name, g_shared->mem_cache.size / 1024, numa_nodes);
} else {
pr_dbg("%s: shared cache buffer size: %" PRIu64 "K\n",
name, g_shared->mem_cache.size / 1024);
}
}
return 0;
}
/*
* stress_cache_free()
* free shared cache buffer
*/
void stress_cache_free(void)
{
if (g_shared->mem_cache.buffer)
(void)stress_munmap_anon_shared((void *)g_shared->mem_cache.buffer, g_shared->mem_cache.size);
if (g_shared->cacheline.buffer)
(void)stress_munmap_anon_shared((void *)g_shared->cacheline.buffer, g_shared->cacheline.size);
}
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